ELECTRICAL POWER SYSTEMS

Electrical power systems for distributing electrical power in arrangements comprising one or more gas turbine engines 101 are described. One such electrical power system comprises: one or more rotary electric machines 111-113, each mechanically coupled to a gas turbine engine spool; a set of converter circuits 203 connected to the one or more rotary electric machines 111-113 for conversion between alternating current (ac) and direct current (dc), wherein the one or more rotary electric machines 111-113 and the set of converter circuits 203 are arranged to output a number R ≥ 2 of dc power channels 206-209, each dc power channel 206-209 having a respective index r = (1, ..., R); and a group of N dc load channels 400-1200 connected to the R dc power channels 206-209 by a switching arrangement 410-1210, wherein each dc load channel 400-1200 has a respective index n = (1, ..., N) and R < N ≤ 2R. The switching arrangement 410-1210 is operable to connect the r-th power channel to the n-th load channel according to the relationship: rn={1,n=1n2andn2+1,1